1. Field of the Invention
The present invention relates to techniques for image processing; and in particular, relates to techniques for overlaying a textual image on a video image.
2. Discussion of the Related Art
In many video applications, a text overlay is often used to superimpose textual information onto a video image. Such a text overlay is used, for example, in a motion picture dubbed in one language, to provide subtitles in a different language. As another example, in a karaoke music video sequence, the lyrics of a song are presented in such text overlays to allow the participants of the karaoke to follow the song in synchrony with the video sequence.
Data compression is used in virtually all video image processing because of the tremendous savings in storage requirements achievable without perceptibly compromising image quality. Many data compression standards have been proposed and used in the industry. In particular, the MPEG (Motion Picture Expert Group) standard has been widely adopted. Algorithms under the MPEG standard perform both interframe and intraframe image compressions. Image processing integrated circuits, which support MPEG compression and decompression algorithms, are available in the market place.